Method and apparatus for conditioning metal sheets and the like



7, 19 5 m. m. mzwmwmm EJWWANW? METHOD AND APPARATUS FOR CONDITIONING METAL SHEETS AND THE LIKE Filed Jan. 18, 1954 N N WC) N N 4L ATTEDZQ VEYS United States Patent METHOD AND APPARATUS FOR CONDITIONING METAL SHEETS AND THE LIKE Ruben 0. Peterson, University Heights, Ohio, assignorio The Osborn Manufacturing Company, Cieveland, Ohio, a corporation of Ohio Application January 18, 1954, Serial No. 404,431 12 Claims. (Cl. 51-23) The present invention relating as indicated to the conditioning of metal sheets, strip, rod and the like has more particular regard to means and methods for attaining such beneficiating effects as the removal of scale and other closely adherent coatings and small slivers, and the rounding of the sharp edges of small pits and scratches, and reducing differences in hardness and associated physical qualities of small adjacent surface areas and small adjacent subsurface component formations, and cleaning and polishing the surface, and reducing surface tension on such articles by brushing action and by the conjoint action. on the surface being treated, of a brush and of auxiliary materials such as abrasive, peening pellets, cleaning and coating materials.

The addition of an abrasive to a brushing operation in order to clean the surface of a metal sheet or like article by an ordinary scouring operation is, of course, well known. Thus, floors have been long cleaned and polished in this manner. It has also been proposed to clean sheet metal plates (see Patent No. 451,263 to Buckman) by similarly supplying an abrasive, e. g. sand, to the surface of the sheet in advance of the application thereto of a rotary brush. However, such simple scouring treatment has not proved eifective for the removal of closely adherent oxide coatings, such as heat formed scale, from sheet or strip steel or rod, in order to prepare such metal for further reduction as by rolling or drawing or to prepare the surface of such metal for plating with another metal, such as tin or zinc, or to receive and retain a paint, acquer, or enamel coating, without employing more costly, objectionable and less beneficial pickling processes.

An aspect of the continuing problem presented, of scale removal by a brushing operation, is evidenced by Patents Nos. 1,440,619 to Noyes et al. and 2,335,196 to Pecsok, which respectively disclose different methods of applying a brush to the surface of a sheet in an endeavor to secure complete scale removal. But other aspects include the removal of small slivers and the sharp edges of pits and scratches which are not removed by prior methods and which when not removed become, upon subsequent rolling, drawing, or the like, thesources of miniature seams and the starting points of fractures when an article made from the metal sheet, strip or rod is subjected to stresses of manufacture and use. Also a phase of the problem involves the minimizing of differences in hardness and associated physical qualities of small adjacent surface areas and small adjacent subsurface component formations, which differences, when permitted to become exaggerated, reduce the facility with which the metal may be worked and reduce some of the desirable qualities of the articles made therefrom. Some commonly used methods and means, such as for example scalebreaking and subsequent pickling to remove the scale, exaggerate such differences and therefore have serious detrimental effects while achieving the main objective.

As indicated above, one object of the present invention is to combine brushing action with applicaiton of an abrasive material in such a manner as will effectually accomplish the removal of scale, small slivers, and other objectionable surface irregularities from metal sheets, strip, rod and similar articles. I have discovered that if such abrasive material be forcibly discharged onto the surface of a sheet simultaneously with the application of a brush thereto or immediately in advance of such application, not only is the cleaning action greatly improved but the power required for brushing greatly reduced. I have further discovered that where, as will be desirable, a rotary brush is employed, such brush itself may be utilized thus forcibly to discharge, by centrifugal action, the abrasive material onto the surface of the sheet without detracting from, but on the contrary greatly increasing, the efliciency of the brushing action proper.

I have found that under certain conditions greatly improved brushing effectiveness is obtained by brushing the concave surface of arcuately flexed sheet, strip, rod or the like in a manner described in detail below, such article being continuously longitudinally advanced and progressively flexed. Furthermore, in such method I may utilize abrasive material either in dry granular form having various degrees of fineness or such abrasive may be carried by a suitable liquid vehicle.

To the accomplishment of the foregoing and related ends, said invention then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawing setting forth in detail certain illustrative embodiments of the invention, these being indicative, hOWBVCIQOf but a few of the various ways in which the principle of the invention may be employed.

In said annexed drawing:

Fig. l is a diagrammatic side elevational view, partly in cross-section, of one form of apparatus embodying the principles of my invention;

Fig. 2 is an enlarged transverse section through a preferred form of rotary brush adapted to be employed therein; and

Fig. 3 is a fragmentary enlarged section of a portion of the brush assembly disclosing means for radial outward flow of surface treating material such as granular abrasive and the like.

Referring now more particularly to Fig. l of the draw ing, the work such as metal strip S may be advanced by means of pairs of power driven rolls 1, 2 and 3, 4 with such strip being flexed in reversed bends by means of arcuate guides 55' and 6. Curved housings 7 and 8 cooperate with such guides and the work itself to enclose cylindrical power driven rotary brushes 9 and 10 mounted within such housings for engagement with the respective concave surfaces of strip S. Granular abrasive or other fiowable treating materials, liquid or gaseous, may be delivered to the working periphery of the brush for application to the surface of the strip, preferably being supplied through the interior of the brush itself. Felt or rubber seals or wipers 11, 12, 13 and 14 help to seal the housings and to prevent abrasive from being transported therefrom on the surfaces of the work. It is desirable that such abrasive be removed from the work before the same passes through the drive rolls which might tend to press the granules of abrasive into the metal surfaces.

Troughs or similar receptacles 15 and 16 may be disposed beneath the respective brushes to .receive excess abrasive dropping down from either side of the Work, and screw conveyors 17 and 18 may be utilized to return such abrasive to a recirculating system.

The brushes may be driven by electric motors such as M directly drivingly connected therewith.

Referring now more particularly to Figs. 2 and 3 of the drawing, it will be seen that the preferred form of cylindrical rotary brush employed may comprise a tubular shaft 19 extending through the closed end portions such as 20 and adapted to rotate relative to the latter. A hollow cylindrical shell 21 is joined to such end portions coaxially with shaft 19, thereby defining a closed rotatable drum having radially outwardly opening apertures 22 therein. Tubular shaft 19 is provided with a plurality of aligned apertures such as 23 therein whereby granular abrasive or other flowable material may be introduced to the interior of shell 21 for delivery to the radially disposed brush material 24. A length of brush strip 25 is mounted within shell 21 for wiping engagement of the bristle ends with the interior of such shell. Such length of brush strip may be mounted on an angularly adjustable hub 26 so that it may be preset in desired angular position. Such brush strip serves the dual purpose of preventing possible clogging of apertures 22 as the shell 21 revolves relative thereto and also controlling the delivery of the abrasive material, for example, to a particular segmental portion of the brush so that the major portion of such abrasive will be projected through the action of centrifugal force in the desired direction against the concave surfaces of the flexed strip S.

Now referring more particularly to Fig. 3 of the drawing, the brush material 24 may be retained in a sheet metal channelform brush back 27 of the general type disclosed in my prior Patent 2,303,386. Reference may also be had to my prior Patent 2,409,309 disclosing a form of rotary brush wherein provision is made for the flow of abrasive or like materials from the interior of the brush body to the working face thereof. As shown in Fig. 3 of the drawing, the brush material 24 is doubled about a retaining wire 28 secured within the channelform back 27 by means of teeth 29 punched in from the sides thereof. The sides of the channelform back are, moreover, deformed by indenting the same in the manner disclosed in such prior Patent 2,409,309 to space such sides apart at intervals for outward flow of the abrasive or other composition through apertures 22 in shell 21 upon which the back 27 of the brush strip is seated.

The direction of maximum discharge of abrasive or other material from the rapidly rotating brush will accordingly be determined both by the location of apertures 23 of the central tubular shaft through which the abrasive or other material is introduced to the interior of shell 21 and also by the disposition of wiper or deflector 25 within such shell. The abrasive may be transported in an appropriate liquid or gaseous vehicle as may be necessary or desirable.

When employing my new apparatus and process for removal of scale from the work, I have discovered that the effectiveness of the brushing action may be greatly increased by previously subjecting the work to a stretching operation effective to stretch the work uniformly beyond its yield point. Ordinarily atleast about 3% elongation will be desired for best results depending on the particular metal involved. Such stretching operation has other advantages and benefits. Among these are reduction of differences in hardness and associated physical qualities of small adjacent surface areas and small adjacent subsurface component formations, and the slight but important outward turning and spacing apart of the sharp edges of pits, scratches and small slivers and more advantageous action thereon by the power operated rotary brushes.

While, as above indicated, the strip or other work may desirably first be stretched beyond its yield point to fragment any scale thereon as well as to regularize the physical properties of the work, prior to operation thereon by my new mechanism, such apparatus is ordinarily more advantageously utilized for the purpose of providing a polished surface, for example. Depending upon the contour of the fixed guides and 6 (which in the case of fairly wide strip need ordinarily engage only the side edge portions thereof), the area of contact between the cylindrical rotary brush and the concave surface of the strip may be varied. As a practical matter, I have found that in order to achieve beneficial results from the employment of my inventionthe region of such contact should lie between 6 and 60 of the brush periphery, this being obtained with a minimum flexing of the brush bristle end portions. In other words, it is usually preferred that the brush closely engage the work throughout the indicated are of contact without the imposition of extremely heavy pressure on the brush to force the brush face to conform to the contour of the work. Accordingly, as shown in Fig. l, the axis of the brush will lie fairly closely adjacent the axis of curvature of the work although naturally somewhat closer to the work itself. The preferred range of arcuate contact for most opera tions will be found to lie between 10 and 20 of the brush periphery.

For certain operations, cylindrical rotary buffs may be employed instead of brushes utilizing brush bristle material.

The above-described arrangement is in sharp contrast to prior art brushing mechanisms and methods wherein the cylindrical rotary brushes are presented to the work (e. g. sheet or strip) with such work extending in a horizontal plane, convexly flexed, or very slightly concavely flexed condition. With such prior known arrangements, it is ordinarily possible to obtain contact between only 2 to 3 degrees of the brush periphery and the work even when heavy pressure is applied upon the brush and the brush bristles correspondingly flexed. As above indicated, the imposition of such heavy pressures is quite an desirable, tending to early break-down of the brush and local over-brushing of the work.

Since the brush bristle ends are more effective in the desired manner when not sharply flexed, I prefer that the pressure imposed on the brush should be insufficient to cause such excessive flexing and consequent dragging of the bristle end portions. The direction of rotation of the brushes should be periodically reversed in order to assist in maintaining the bristle ends sharp and uniform. With the large area of contact obtained by my arrangement, it becomes possible to traverse the work relatively rapidly and still obtain a thorough cleaning and polishing action. The speed of rotation of theb'rushes will depend on a variety of circumstances including the diameters of the same and the type of brushing operation involved, but may ordinarily range from about 1800 to 9000 R. P. M. While the brush bristle material may frequently be crimped wire, a large variety of bristle materials, well known in the art, is available for different purposes.

This application is a continuation-in-part of my copending applications Serial No. 126,408, filed November 9, 1949, now Patent No. 2,680,938 dated June 15, 1954, and Serial No. 221,906, filed April 19, 1951, now Patent No. 2,666,282 dated January 19, 1954, which are in turn continuations-in-part of my application Serial No. 668,391 filed May 9, 1946, in turn a continuation-in-part of Serial No. 632,831 filed December 5, 1945, and Serial No. 437,648 filed April 4, 1942. Such applications Serial No. 437,648; 632,831 and 668,391 have been abandoned without prejudice in favor of application Serial No. 221,906.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

I therefore particularly point out and distinctly claim as my invention:

1. The method of surface beneficiating a metal article which comprises progressively locally flexing such article to concave form, and brushing the concave surface of such flexed article with a rotary brush disposed on an axis parallel to the axis of flexing and thereby having a sub-' stantial area of its brush face periphery continually contacting such concave surface.

2. The method of'surface beneficiating a flat metal strip which comprises continuously longitudinally advancing such strip, progressively arcuately flexing such advancing strip, brushing the concave surface of such arcuately flexed portion of such continuously advancing strip with a rotary brush disposed on an axis transversely of such strip and thereby having a substantial area of its brush face periphery continually contacting such concave surface, and simultaneously supplying a surface-treating composition to such area of contact.

3. Apparatus for surface-conditioning elongated metal articles comprising means operative continuously to ad- Vance such article, means adapted to direct such advancing article in a curved path, and a power-driven rotary brush disposed and arranged with its axis parallel to and closely adjacent the axis of such curvature, the diameter of such brush being selected to bring the outer periphery thereof into engagement with a substantial longitudinal portion of the concave surface of such article.

4. Apparatus for surface-conditioning elongated metal articles such as strip and the like comprising power-driven means operative continuously longitudinally to advance such article, guide means adapted to direct such continuously advancing article in a curved, substantially arcuate, path, and a power-driven rotary brush having radially extending brush material, said brush being disposed and arranged with its axis closely adjacent the axis of the arc of curvature thus imposed on such strip and said brush having a diameter selected to bring the outer periphery thereof into engagement with the concave surface of such article throughout a continuous arc of at least degrees.

5. Apparatus in accordance with claim 4, together with means for delivering a surface treating composition to the working face of said brush.

6. Apparatus in accordance with claim 4, together with a housing enclosing said brush except in the general region where said brush is adapted to engage such article.

7. Apparatus in accordance with claim 4, together with means for introducing a flowable surface treating composition internally of said brush for delivery to the working face thereof under the influence of centrifugal force, said brush having a hollow interior and openings leading therefrom to such face.

8. The method of surface beneficiating an elongated metal article such as strip and the like which comprises continuously longitudinally advancing the same, arcuately flexing such advancing strip, and brushing the concave surface of the flexed portion of such strip by engagement with the bristle material of a power-driven cylindrical brush simultaneously throughout a longitudinally arcuate portion of at least 10 degrees.

9. The method of surface beneficiating an elongated metal article such as strip and the like which comprises continuously longitudinally advancing the same, arcuately flexing such advancing strip, and brushing the concave surface of the flexed portion of such strip simultaneously throughout a longitudinally arcuate portion of at least 10 degrees with a cylindrical rotary brush having radially extending brush material, the peripheral face of such brush being maintained in engagement with such concave surface throughout such arcuate extent.

10. Apparatus for surface-conditioning elongated metal articles comprising means operative continuously to advance such article, means adapted to direct such article in a curved path, a power-driven rotary brush disposed and arranged with its axis parallel to and adjacent the axis of such curvature, the diameter of such brush being selected to bring the outer periphery thereof into engagement with a substantial longitudinal portion of the concave surface of such article, and means operative forcefully to impel discrete abrasive particles against such portion of such surface thus engaged by said brush.

11. Apparatus for surface-conditioning elongated metal articles such as strip and the like comprising power-driven means operative continuously longitudinally to advance such article, means adapted to flex such continuously advancing article in a curved path, and a power-driven generally cylindrical rotary tool having a cylindrical peripheral working surface capable of yielding somewhat upon engagement with the work, said tool being disposed with its axis of rotation adjacent the axis of curvature of such article and having a diameter selected to bring the periphery thereof into working engagement with the concave surface of such article throughout a continuous arcuate portion of such periphery of from 6 to 60 degrees.

12. Apparatus for surface-conditioning elongated metal articles such as strip and the like comprising power-driven means operative continuously longitudinally to advance such article, means adapted to flex such continuously advancing article in a curved path, and a power-driven generally cylindrical rotary tool having a cylindrical peripheral working surface capable of yielding somewhat upon engagement with the work, said tool being disposed with its axis of rotation adjacent the axis of curvature of such article and having a diameter selected to bring the periphery thereof into Working engagement with the concave surface of such article throughout a continuous arcuate portion of such periphery of from 10 to 20 degrees.

References Cited in the file of this patent UNITED STATES PATENTS 293,011 Hall et a1. Feb. 5, 1884 451,263 Buckman Apr. 28, 1891 492,099 Nelson Feb. 21, 1893 869,478 Broderick Oct. 29, 1907 1,884,791 McCrery Oct. 25, 1932 1,978,681 MacGregor Oct. 30, 1934 2,173,364 Jesser Sept. 19, 1939 2,200,592 Coddington May 14, 1940 2,221,348 Hershey et al Nov. 12, 1940 2,429,742 Barnes Oct. 28, 1947 2,445,492 Pentecost July 20, 1948 2,549,043 Arthur Apr. 17, 1951 2,666,282 Peterson Jan. 19, 1954 2,680,938 Peterson June 15, 1954 FOREIGN PATENTS 49,730 Germany Nov. 22, 1889 632,771 France Oct. 10, 1927 

1. THE METHOD OF SURFACE BENEFICIATING A METAL ARTICLE WHICH COMPRISES PROGRESSIVELY LOCALLY FLEXING SUCH ARTICLE TO CONCAVE FORM, AND BRUSHING THE CONCAVE SURFACE OF SUCH FLEXED ARTICLE WITH A ROTARY BRUSH DISPOSED ON AN AXIS PARALLEL TO THE AXIS OF FLEXING AND THEREBY HAVING A SUBSTANTIAL AREA OF ITS BRUSH FACE PERIPHERY CONTINUALLY CONTACTING SUCH CONCAVE SURFACE. 